Smart grids may manage power efficiently, but they also gather private data concerning each household's energy use -- data that should be protected.

It knows how often you use your microwave, how many loads of laundry you do every week, what kind of television you own and even how often you shower. It can tell how many people live in your home, what time they go to bed and when the house is empty. All of this information and more is gathered by smart grid meters — and companies are already trying to profit from it, according to the Denver Post.

The smart grid will replace the aging U.S. electrical network, adding monitoring, analysis, control and communication capabilities that ensure efficient transmission and use of electricity, and help reduce energy consumption.

The information gathered by smart meters every 15 seconds and instantly transmitted to utility companies through Wi-Fi, broadband or fiber-optic cable makes the power system less wasteful and more reliable, but privacy advocates are concerned about how that data will be protected.

"Insufficient oversight could lead to an unprecedented invasion of consumer privacy,” writes Elias Quinn in a smart grid privacy study for the Colorado Public Utilities Commission.

About 200,000 smart meters have already been installed in Colorado with 52 million more slated for installation across the nation by 2015, and data from those meters is already being eyed by law enforcement, government agencies and private corporations like Google and Microsoft.

The information could be used in all kinds of ways, legitimate or not, from cities seeking broad information about how well energy-efficiency programs are working to burglars looking for expensive electronics.

Law enforcement agencies want to use smart meters to spot potential marijuana-growing operations or the location of an underground sweatshop. Companies hope the data will help them target marketing to consumers.

Utility companies like Xcel in Colorado claim that the data collected by smart meters stays between them and the consumer, and that all outside access requests have been denied. Regardless of that promise, organizations like the Colorado Office of Consumer Counsel are seeking new state rules to protect consumer privacy.

Just as it was with the Internet, privacy protection will have to be built into the smart grid from the start, says Bill Levis, director of the Colorado Office of Consumer Counsel.